scholarly journals The Importance of Mimicking Dermal-Epidermal Junction for Skin Tissue Engineering: A Review

2021 ◽  
Vol 8 (11) ◽  
pp. 148
Author(s):  
Mina Aleemardani ◽  
Michael Zivojin Trikić ◽  
Nicola Helen Green ◽  
Frederik Claeyssens
Keyword(s):  
Tissue Engineering ◽  
Cell Function ◽  
Multiple Roles ◽  
Primary Role ◽  
Skin Substitutes ◽  
Anatomical Structures ◽  
And Function ◽  
Bioengineered Skin ◽  
Physical Boundary

There is a distinct boundary between the dermis and epidermis in the human skin called the basement membrane, a dense collagen network that creates undulations of the dermal–epidermal junction (DEJ). The DEJ plays multiple roles in skin homeostasis and function, namely, enhancing the adhesion and physical interlock of the layers, creating niches for epidermal stem cells, regulating the cellular microenvironment, and providing a physical boundary layer between fibroblasts and keratinocytes. However, the primary role of the DEJ has been determined as skin integrity; there are still aspects of it that are poorly investigated. Tissue engineering (TE) has evolved promising skin regeneration strategies and already developed TE scaffolds for clinical use. However, the currently available skin TE equivalents neglect to replicate the DEJ anatomical structures. The emergent ability to produce increasingly complex scaffolds for skin TE will enable the development of closer physical and physiological mimics to natural skin; it also allows researchers to study the DEJ effect on cell function. Few studies have created patterned substrates that could mimic the human DEJ to explore their significance. Here, we first review the DEJ roles and then critically discuss the TE strategies to create the DEJ undulating structure and their effects. New approaches in this field could be instrumental for improving bioengineered skin substitutes, creating 3D engineered skin, identifying pathological mechanisms, and producing and screening drugs.

scholarly journals Non-Coding RNA in Pancreas and β-Cell Development

2018 ◽  
Vol 4 (4) ◽  
pp. 41 ◽  
Author(s):  
Wilson K. M. Wong ◽  
Anja E. Sørensen ◽  
Mugdha V. Joglekar ◽  
Anand A. Hardikar ◽  
Louise T. Dalgaard
Keyword(s):  
Cell Function ◽  
Islet Cells ◽  
Current Knowledge ◽  
Cell Development ◽  
Pancreas Development ◽  
Β Cell ◽  
Neighboring Gene ◽  
Non Coding Rnas ◽  
And Function

In this review, we provide an overview of the current knowledge on the role of different classes of non-coding RNAs for islet and β-cell development, maturation and function. MicroRNAs (miRNAs), a prominent class of small RNAs, have been investigated for more than two decades and patterns of the roles of different miRNAs in pancreatic fetal development, islet and β-cell maturation and function are now emerging. Specific miRNAs are dynamically regulated throughout the period of pancreas development, during islet and β-cell differentiation as well as in the perinatal period, where a burst of β-cell replication takes place. The role of long non-coding RNAs (lncRNA) in islet and β-cells is less investigated than for miRNAs, but knowledge is increasing rapidly. The advent of ultra-deep RNA sequencing has enabled the identification of highly islet- or β-cell-selective lncRNA transcripts expressed at low levels. Their roles in islet cells are currently only characterized for a few of these lncRNAs, and these are often associated with β-cell super-enhancers and regulate neighboring gene activity. Moreover, ncRNAs present in imprinted regions are involved in pancreas development and β-cell function. Altogether, these observations support significant and important actions of ncRNAs in β-cell development and function.

scholarly journals A Triple Threat? The Role of Diet, Nutrition, and the Microbiota in T1D Pathogenesis

2021 ◽  
Vol 8 ◽  
Author(s):  
Emma E. Hamilton-Williams ◽  
Graciela L. Lorca ◽  
Jill M. Norris ◽  
Jessica L. Dunne
Keyword(s):  
Beta Cell ◽  
Intestinal Microbiota ◽  
Beta Cell Function ◽  
Cell Function ◽  
The Body ◽  
Islet Autoimmunity ◽  
Potential Mechanism ◽  
Modifiable Factors ◽  
And Function

In recent years the role of the intestinal microbiota in health and disease has come to the forefront of medical research. Alterations in the intestinal microbiota and several of its features have been linked to numerous diseases, including type 1 diabetes (T1D). To date, studies in animal models of T1D, as well as studies in human subjects, have linked several intestinal microbiota alterations with T1D pathogenesis. Features that are most often linked with T1D pathogenesis include decreased microbial diversity, the relative abundance of specific strains of individual microbes, and altered metabolite production. Alterations in these features as well as others have provided insight into T1D pathogenesis and shed light on the potential mechanism by which the microbiota plays a role in T1D pathogenesis, yet the underlying factors leading to these alterations remains unknown. One potential mechanism for alteration of the microbiota is through diet and nutrition. Previous studies have shown associations of diet with islet autoimmunity, but a direct contributing factor has yet to be identified. Diet, through introduction of antigens and alteration of the composition and function of the microbiota, may elicit the immune system to produce autoreactive responses that result in the destruction of the beta cells. Here, we review the evidence associating diet induced changes in the intestinal microbiota and their contribution to T1D pathogenesis. We further provide a roadmap for determining the effect of diet and other modifiable factors on the entire microbiota ecosystem, including its impact on both immune and beta cell function, as it relates to T1D. A greater understanding of the complex interactions between the intestinal microbiota and several interacting systems in the body (immune, intestinal integrity and function, metabolism, beta cell function, etc.) may provide scientifically rational approaches to prevent development of T1D and other childhood immune and allergic diseases and biomarkers to evaluate the efficacy of interventions.

scholarly journals Evolution and function of the hominin forefoot

2018 ◽  
Vol 115 (35) ◽  
pp. 8746-8751 ◽  
Author(s):  
Peter J. Fernández ◽  
Carrie S. Mongle ◽  
Louise Leakey ◽  
Daniel J. Proctor ◽  
Caley M. Orr ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Common Ancestor ◽  
Bipedal Locomotion ◽  
Last Common Ancestor ◽  
Primary Role ◽  
Anthropoid Primates ◽  
And Function ◽  
Metatarsophalangeal Joints ◽  
Selection Of

The primate foot functions as a grasping organ. As such, its bones, soft tissues, and joints evolved to maximize power and stability in a variety of grasping configurations. Humans are the obvious exception to this primate pattern, with feet that evolved to support the unique biomechanical demands of bipedal locomotion. Of key functional importance to bipedalism is the morphology of the joints at the forefoot, known as the metatarsophalangeal joints (MTPJs), but a comprehensive analysis of hominin MTPJ morphology is currently lacking. Here we present the results of a multivariate shape and Bayesian phylogenetic comparative analyses of metatarsals (MTs) from a broad selection of anthropoid primates (including fossil apes and stem catarrhines) and most of the early hominin pedal fossil record, including the oldest hominin for which good pedal remains exist, Ardipithecus ramidus. Results corroborate the importance of specific bony morphologies such as dorsal MT head expansion and “doming” to the evolution of terrestrial bipedalism in hominins. Further, our evolutionary models reveal that the MT1 of Ar. ramidus shifts away from the reconstructed optimum of our last common ancestor with apes, but not necessarily in the direction of modern humans. However, the lateral rays of Ar. ramidus are transformed in a more human-like direction, suggesting that they were the digits first recruited by hominins into the primary role of terrestrial propulsion. This pattern of evolutionary change is seen consistently throughout the evolution of the foot, highlighting the mosaic nature of pedal evolution and the emergence of a derived, modern hallux relatively late in human evolution.

scholarly journals The Modern Western Diet Rich in Advanced Glycation End-Products (AGEs): An Overview of Its Impact on Obesity and Early Progression of Renal Pathology

Nutrients ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1748 ◽  
Author(s):  
Arianna Bettiga ◽  
Francesco Fiorio ◽  
Federico Di Marco ◽  
Francesco Trevisani ◽  
Annalisa Romani ◽  
...  
Keyword(s):  
Chronic Diseases ◽  
Advanced Glycation End Products ◽  
Cell Function ◽  
Advanced Glycation ◽  
Covalent Bonds ◽  
Physiological Processes ◽  
Glycation End Products ◽  
End Products ◽  
And Function

Advanced glycation end-products (AGEs) are an assorted group of molecules formed through covalent bonds between a reduced sugar and a free amino group of proteins, lipids, and nucleic acids. Glycation alters their structure and function, leading to impaired cell function. They can be originated by physiological processes, when not counterbalanced by detoxification mechanisms, or derive from exogenous sources such as food, cigarette smoke, and air pollution. Their accumulation increases inflammation and oxidative stress through the activation of various mechanisms mainly triggered by binding to their receptors (RAGE). So far, the pathogenic role of AGEs has been evidenced in inflammatory and chronic diseases such as chronic kidney disease, cardiovascular disease, and diabetic nephropathy. This review focuses on the AGE-induced kidney damage, by describing the molecular players involved and investigating its link to the excess of body weight and visceral fat, hallmarks of obesity. Research regarding interventions to reduce AGE accumulation has been of great interest and a nutraceutical approach that would help fighting chronic diseases could be a very useful tool for patients’ everyday lives.

scholarly journals The key role of prefrontal cortex structure and function

2006 ◽  
Vol 29 (1) ◽  
pp. 22-22
Author(s):  
Antonino Raffone ◽  
Gary L. Brase
Keyword(s):  
Prefrontal Cortex ◽  
Species Differences ◽  
Structure And Function ◽  
Primary Role ◽  
Neural Connectivity ◽  
Neuronal Connectivity ◽  
Connectivity Patterns ◽  
Brain Expansion ◽  
And Function

The tension between focusing on species similarities versus species differences (phylogenetic versus adaptationist approaches) recurs in discussions about the nature of neural connectivity and organization following brain expansion. Whereas Striedter suggests a primary role for response inhibition, other possibilities include dense recurrent connectivity loops. Computer simulations and brain imaging technologies are crucial in better understanding actual neuronal connectivity patterns.

scholarly journals Chemokines: understanding their role in T-lymphocyte biology

1998 ◽  
Vol 333 (3) ◽  
pp. 457-470 ◽  
Author(s):  
Stephen G. WARD ◽  
John WESTWICK
Keyword(s):  
T Lymphocytes ◽  
Chemokine Receptors ◽  
Protein Tyrosine Kinase ◽  
Cell Function ◽  
Signalling Pathways ◽  
Cc Chemokine ◽  
Intracellular Signalling Pathways ◽  
And Function ◽  
Hiv 1

The chemokines are a complex superfamily of small, secreted proteins that were initially characterized through their chemotactic effects on a variety of leucocytes. The superfamily is divided into families based on structural and genetic considerations and have been termed the CXC, CC, C and CX3C families. Chemokines from these families have a key role in the recruitment and function of T lymphocytes. Moreover, T lymphocytes have also been identified as a source of a number of chemokines. T lymphocytes also express most of the known CXC and CC chemokine receptors to an extent that depends on their state of activation/differentiation and/or the activating stimuli. The expression of two chemokine receptors, namely CXCR4 and CCR5, together with the regulated production of their respective ligands, appears to be extremely important in determining sensitivity of T cells to HIV-1 infection. The intracellular events which mediate the effects of chemokines, particularly those elicited by the CC chemokine RANTES, include activation of both G-protein- and protein tyrosine kinase-coupled signalling pathways. The present review describes our current understanding of the structure and expression of chemokines and their receptors, the effects of chemokines on T-cell function(s), the intracellular signalling pathways activated by chemokines and the role of certain chemokines and chemokine receptors in determining sensitivity to HIV-1 infection.

scholarly journals Role of the Rho-ROCK (Rho-Associated Kinase) Signaling Pathway in the Regulation of Pancreatic β-Cell Function

Endocrinology ◽  
2008 ◽  
Vol 150 (5) ◽  
pp. 2072-2079 ◽  
Author(s):  
Eva Hammar ◽  
Alejandra Tomas ◽  
Domenico Bosco ◽  
Philippe A. Halban
Keyword(s):  
Extracellular Matrix ◽  
Insulin Secretion ◽  
Actin Cytoskeleton ◽  
Cell Function ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Β Cell Function ◽  
Glucose Stimulated Insulin Secretion ◽  
And Function

Extracellular matrix has a beneficial impact on β-cell spreading and function, but the underlying signaling pathways have yet to be fully elucidated. In other cell types, Rho, a well-characterized member of the family of Rho GTPases, and its effector Rho-associated kinase (ROCK), play an important role as downstream mediators of outside in signaling from extracellular matrix. Therefore, a possible role of the Rho-ROCK pathway in β-cell spreading, actin cytoskeleton dynamics, and function was investigated. Rho was inhibited using a new cell-permeable version of C3 transferase, whereas the activity of ROCK was repressed using the specific ROCK inhibitors H-1152 and Y-27632. Inhibition of Rho and of ROCK increased spreading and improved both short-term and prolonged glucose-stimulated insulin secretion but had no impact on basal secretion. Inhibition of this pathway led to a depolymerization of the actin cytoskeleton. Furthermore, the impact of the inhibition of ROCK on stimulated insulin secretion was acute and reversible, suggesting that rapid signaling such as phosphorylation is involved. Finally, quantification of the activity of RhoA indicated that the extracellular matrix represses RhoA activity. Overall these results show for the first time that the Rho-ROCK signaling pathway contributes to the stabilization of the actin cytoskeleton and inhibits glucose-stimulated insulin secretion in primary pancreatic β-cells. Furthermore, they indicate that inhibition of this pathway might be one of the mechanisms by which the extracellular matrix exerts its beneficial effects on pancreatic β-cell function.

scholarly journals Beyond “Big Eaters”: The Versatile Role of Alveolar Macrophages in Health and Disease

2021 ◽  
Vol 22 (7) ◽  
pp. 3308
Author(s):  
Miriam Hetzel ◽  
Mania Ackermann ◽  
Nico Lachmann
Keyword(s):  
Alveolar Macrophages ◽  
Cell Types ◽  
Multiple Roles ◽  
Pulmonary Diseases ◽  
Congenital Diseases ◽  
Organ Specific ◽  
Macrophage Dysfunction ◽  
Macrophage Populations ◽  
And Function

Macrophages act as immune scavengers and are important cell types in the homeostasis of various tissues. Given the multiple roles of macrophages, these cells can also be found as tissue resident macrophages tightly integrated into a variety of tissues in which they fulfill crucial and organ-specific functions. The lung harbors at least two macrophage populations: interstitial and alveolar macrophages, which occupy different niches and functions. In this review, we provide the latest insights into the multiple roles of alveolar macrophages while unraveling the distinct factors which can influence the ontogeny and function of these cells. Furthermore, we will highlight pulmonary diseases, which are associated with dysfunctional macrophages, concentrating on congenital diseases as well as pulmonary infections and impairment of immunological pathways. Moreover, we will provide an overview about different treatment approaches targeting macrophage dysfunction. Improved knowledge of the role of macrophages in the onset of pulmonary diseases may provide the basis for new pharmacological and/or cell-based immunotherapies and will extend our understanding to other macrophage-related disorders.

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